IIS & FTP

I am trying to install my FTP srver through IIS on my XP
Pro machine. I having a lot of problems

1. In IIS the folders are set up as FTP Sites-Default
FTP Site. On both of these folders I have the option to
allow/disallow anonymous connections. Where and when is
it appropriate to do this. Do I do it on the "higher"
folder, the FTP Sites one, or the "lower" folder, the
Default FTP Site

2. All I can figure out is that I can either:
A. Allow all connections by allowing anonymous
connections or
B. Allow any user account on my machine to get in

Is there a way to only allow a certain group of users to
connect or only specific user accounts?